TI ADS1115 16 bit
Let me be the first to say that unless you are a very good engineer, using a 16-bit adc can be quite a challenge. And unless you are some analog god, using a 24-bit adc can be downright impossible.
Rather than increasing the bits, you should think if you need that much resolution and if that high of a resolution makes sense for your application (for example, is it even that accurate?).